BZOJ4070: [Apio2015] The skyscrapers of Jakarta

Idea  {

For every dog on the floor . The most intuitive method is to split a point into an N -Dog Point, and then the shortest way.

However, I was also drunk in the blast space.

So we're going to use a tune-up of the chunking.

Should be the connected state of each point. Just a little bit.

Divide a building into 1- block long layers, and for any dog with the same number of layers, you can  walk in a high-altitude mess.

But what is the length of the p> block? ------ directly connected to the edge.

Then YY , dealing with each dog's activation relationship. SPFA can do it.

}

　

#include <bits/stdc++.h> #define RG register#define il inline #define N 5500000#define Inf 2#define U unsigned short#d Efine POS (i,j) (i*n+j) using namespace std;struct ed{int nxt,to,c;} E[30005*500];int head[30005*105],dis[30005*105],n,m,q,b,s,t;bool in[30005*105];int tot;void Add (int u,int v,int c) {e[ tot].nxt=head[u];e[tot].to=v;e[tot].c=c;head[u]=tot++;} void Add (int u,int v,int c) {Add (U,v,c), add (v,u,c);}  void Spfa () {queue<int>que;memset (dis,inf,sizeof (DIS)); int ss=dis[t];  Que.push (s), in[s]=true,dis[s]=0;    while (!que.empty ()) {int U=que.front (); Que.pop (); in[u]=false; for (int i=head[u];i!=-1;i=e[i].nxt) if (dis[e[i].to]>dis[u]+e[i].c) {int v=e[i].to;dis[v]=dis[u]+e[i].c;if (!in[v      ]) Que.push (v), in[v]=true;  }}if (DIS[T]==SS) cout<< "-1"; else cout<<dis[t];}  int main () {freopen ("skyscraper.in", "R", stdin);  Freopen ("Skyscraper.out", "w", stdout);  memset (head,-1,sizeof (head)); cin>>n>>m;  U int len=min ((int) sqrt (n), 100); for (RG int i=1;i<=len;++i) for (int j=1;j<=n;++j) Add (POS (i,j), j,0);  for (RG int i=1;i<=len;++i) for (int j=1;j<=n-i;++j) ADD (POS (I,J), POS (i,j+i), 1);    for (RG int i=1;i<=m;++i) {int b,p;    cin>>b>>p;b++;    if (i==1) s=b;if (i==2) t=b;    if (P<=len) Add (B,pos (p,b), 0);      else {for (int j=1;j*p+b<=n;++j) Add (B,B+J*P,J);    for (int j=1;b-j*p>0;++j) Add (B,B-J*P,J);  }}SPFA (); return 0;}

　　

　

BZOJ4070: [Apio2015] The skyscrapers of Jakarta